Known surf pools comprise a caisson divided into a plurality of wave generating chambers, and a ventilator space with a source of compressed air capable of alternately effecting aspiration and expiration above the water surfaces in the wave generating chambers via a conduit system provided with air inlet and air outlet valves. One such wave generator is shown in U.S. Pat. No. 3,629,877. The particular feature of this prior wave generator is that the maximum wave heights are located in the middle of the swimming pool. Apart from the number of wave generating chambers of a given width, this is achieved by virtue of a swivel channel forcing air alternately into two adjacent wave generating chambers. For this purpose these swivel channels are reciprocated by a pneumatically controlled linkage. As this reciprocation must be effected at a high rate, and a relatively high mass is involved, a relatively high amount of power is required. Moreover, it is not a simple matter to blow air into two adjacent wave generating chambers simultaneously, should this be desired to generate a particular wave pattern.
In this specification the term "aspiration" means the process in which the space above the water in the wave generating chambers is charged with compressed air from a blower, and the term "expiration" means the process in which excess air is let off from the wave generating chambers under the influence of the pressure of the water in the pool.
It is an object of the present invention to make the prior wave generator of simpler and hence of less expensive design, and yet provide more possibilities for varying the wave pattern.